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I made that fancy collet to grab the bush hog shaft, and it didn't work
I dont gots any pics.................CAUSE I LOST THE OLD ONES.Anyways, I'm looking at fixing the doggone collet so it HOPEFULLY will work. Can't have just one slot, it needs as many slots as there are jaws on the chuck. I THINK
Can't take the runout out of the setup on the lathe..................so it's gotta be that the collet, only having one slot, is catching on two jaws, but preventing the other 2 jaws from closing properly and eliminating runout. Once the collet is closed, the remaining circumference is "locked up" so to speak. IT'S GOTTA HAVE 4 SLOTS.
Reply:News at 10
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With only one slot, the chuck jaws can't grab it right, in order to close it evenly around the shaft. At least that's what I'm thinkin'. I fooled around a lifetime trying to do the setup, and this has to be the problem. All that time down the drain today. Even put the shaft on v blocks to make certain it's straight. Gawd what a clusterfk
Cut 3 more slots this evening, and see if it works out. GEEZ!!!!!!!!!!!!!!I shoulda been clued in when the shaft kept trying to walk. Interesting phenomenon to see a live center spin with a wobble
Reply:How about just turn the diameter thinner?Should have nuff power to grab then?Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:
Originally Posted by MinnesotaDave
How about just turn the diameter thinner?Should have nuff power to grab then?
Reply:Use a 4 jaw chuck?Murphy's Golden Rule: Whoever has the gold, makes the rules.
Reply:Almost 4:00AM, and I'm just draggin' my butt into the house
I sliced the collet into 4 sections. One for each chuck jaw.
Placing the 4 slices on the threaded portion of the shaft was a booger. I finally taped them so I could get the whole mess in the chuck without little slices falling all over the place
I literally spent the whole stinkin' night chasing a few thousands. GEEZ!!!! I could not get the runout down below .020 at the far end of the shaft, no matter how I fooled with it. The first bearing journal was coming in at about .0015 runout, but that damn far end was whipping around like a NOODLE. And the tailstock was only able to take a few thousands wobble out of the shaft.I finally got fed up, and frustrated. Sat down in front of the lathe, and just looked at it................like I might be able to divine some hidden secrets from the metal
For S&G's, I turned it on while I was sitting there, and REALLY looked at how the shaft was spinning. THE END OF THE TAPER RIGHT NEXT TO THE CHUCK WAS MOVING LIKE A SNAKE................EVEN THOUGH THE BEARING JOURNAL WAS RUNNING TRUE.I was getting almost .010 at the the very end of the thin part of the taper, about 1/4" from the chuck. HELL.................that don't look right!!!!So, I figure WTH, might as well try to set the runout at the face of the chuck on the taper. Fought it for a doggone long time, and finally settled on about .002 runout..............which is A LOT for a 4 jaw. I just couldn't get it down to .001ish.This brought the runout at the far end down to about .010 . Hell, it's better than .020...........................Switched to a dead center in the tailstock, instead of the live center, and slammed 'er into the shaft center. BROUGHT THE RUNOUT DOWN TO .004
On a shaft that's been beat for almost half a century, that's pretty friggin good. I can turn it fairly concentric at that runout, or at least get close.
I was able to turn it down to the next thread size. It was 1 9/16-18..................I was able to salvage enough of the metal to come in at the proper diameter for 1 1/2-18 . There's just a ghost of the original thread on the surface, but it's within .002 of the maximum major diameter. KEWL!!!!
I'm glad I ordered the 1144 Stressproof. The original nut is hard enough to resist a file. 1144 comes in at 100Ksi tensile, and a fairly hard Brinnell/Rockwell. It should be close to what's needed.Anyways............it's almost a waste of time goin' to bed at this time of the morning
Reply:For short lengths, I'm forced to buy off of Ebay. Alro will have the proprietary grade/brand with MTR's, but they won't sell short lengths unless you show up with an armored car full of greenbacks. Niagara is the maker of the real deal, 1144 is the industry generic.http://www.niagaralasalle.com/product-stressproof.html2.50x12.00 piece cost $42 including shipping. Cheaper than a new shaft, if all goes well.Get to threading later in the day.............gotta go inspect some used S8 beams (around $350 for 3 20' sections)
Reply:
Originally Posted by farmersammm
I made that fancy collet to grab the bush hog shaft, and it didn't work
I dont gots any pics.................CAUSE I LOST THE OLD ONES.Anyways, I'm looking at fixing the doggone collet so it HOPEFULLY will work. Can't have just one slot, it needs as many slots as there are jaws on the chuck. I THINK
Can't take the runout out of the setup on the lathe..................so it's gotta be that the collet, only having one slot, is catching on two jaws, but preventing the other 2 jaws from closing properly and eliminating runout. Once the collet is closed, the remaining circumference is "locked up" so to speak. IT'S GOTTA HAVE 4 SLOTS.
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Originally Posted by 123weld
theshop i worked in the 90's, was one of the biggest shops around, they had about a quater mill in tooling alone. for ur setup, i woulda walked over to a can, that had various strips of lead intended for the jaws , cut about .5+ wide, and about .125 thick. just lay b/t jaws/thread (whatever), and were reused many times. it worked great
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The chips from removing the threads were short, with very little curl. I have no idea what Rockwell the shaft is. I can't dent it with a file. The carbide insert screamed a bit at the end of the cuts when it hit the shoulder. Because of the keyway, I kept the speed down to 190rpm, with a slow feed. Was worried about ruining the insert on the interrupted cuts.With the thread removed, and the surface machined barely below the minor diameter of the old thread, the metal appears softer. I can dent it with a file. But with effort.I'm thinking that maybe the shaft isn't through hardened, and I may be getting near the case boundary. Even at this depth, I kept the depth of cut to .005 to be safe, and not hit the keyways too hard.If I'm coming out of the hardened area, into some softer material, I'm having to make a decision between HSS, and carbide, for threading.I like HSS, but if this stuff is too hard, I'm worried the bit might dull before the thread is finished..........then I gotta pick up the thread when I sharpen the tool. Not something I care to do if the thread is near completion. So.....................................I guess it's carbide. Carbide doesn't work well on the 1018 I'm used to working with, but I'd wager the shaft metal is a more machinable alloy, so the carbide should do fine. (I hope
)
I have a sort of obsolete on-edge threading tool that I picked up as part of the NOS Dorian toolpost deal coupla years back. I used it when trying to repair the thread, and it cut the material really nice. AND IT'S INDEXABLE SHOULD I CHIP A CUTTER.The old tool takes TNMC 32NV inserts, which are still out there, but seeming to be going away.I'm looking at the Kennametal NT3 insert on edge system (Top Notch I think they call it). It's modern, and has a good availability of inserts in different grades. One grade, in particular, is made for turning hardened steel..........grade KU25T. Maybe Santa will drop one down the soil stack
K'kins always gets me a ton of feed for Xmas
Reply:
Originally Posted by farmersammm
That collet was a ton of work.
Reply:Wound up working into the night again. Last night messed up my sleep pattern, took a nap that was supposed to last an hour............and wound up sleeping till sometime in the afternoon
It all started fairly good
Then it rapidly went down the crapper.The keyways almost killed the lathe, and destroyed 3 inserts (all 3 cutting edges on each one)When the tool hit the keyways (2), the shock broke the tips of the tools, and drove the cross slide back against the leadscrew...NOTICEABLY. Whole damn cross slide started bucking. WITH A STINKIN' .005 DEPTH OF CUT AT 70RPM
When the tips held up, they cut, and no problems other than slamming the leadscrew. Dropping the DOC to .003 helped, but the tips still broke. This is some miserable hard material
Cranking the lathe manually solved the problem
No shock to break the tip of the tool, and it cut smoothly. But you can't hand crank a lathe that has splash lubricated bearings........eventually they run out of oil if the machine isn't running at speed
Got the Dremel out, and ground infeed ramps on both keyways. Solved the problem if you kept the DOC at .003 . Still trashed an additional insert though.HSS might have held up better, but we'll never know. If the tool had broken, or dulled.........................good luck trying to come back in on the thread after removing the tool from the holder. Maybe at the beginning of the process, but not near the end.Anyways..........got 'er done finally
The material cut like crap, resulting in a lot of work cleaning up the threads, but I can live with it.............Hell.........I gotta live with it
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Missed my pitch diameter by slightly less than .004, which resulted from a grabby spring pass. The material is so hard that the tool either tends to rub, or if it catches a good edge, will cut to a depth deeper than what you set the compound for. The spring passes were a total nightmare............tool rubs instead of cutting, forcing you to advance the compound to try and dig in.................THEN THE DAMN CUTTER GOES ALL THE WAY TO CHINA
Basically a combination of hard material, and a less than rigid lathe. I don't see at as a major issue, because this is a one-off with a custom nut. I can smoogie the nut a bit tighter when I make it.
Was a pleasure to finally take the collet off. End of story, outta here, get lost, don't let the door hit ya on the way out............................................... ...Like suggested..........I might just hang these up somewhere to remind me of what a PITA this has been
One more fly in the ointment.......................................
Downsizing the thread diameter isn't a problem, nor is making a new nut..................but the damn lock washer is too big now. When I make the nut, I'll have to leave a lip in the center to centralize the washer against the pinion. Otherwise, the tab that sits in the keyway will wander , and the nut won't be locked. I might get lucky, and source a washer that's the correct size, but it's a gamble.
Reply:Fitting a piece of keystock and temporarily retaining it with loctite may have helped that situation if it fit tight enough before you turned the diameter. I had an internal bore on a hub I had to enlarge and that worked well.
Reply:jb weld or similar in the keyway? take the shock loading off the tooltip?
Reply:You've got a welder. Gob snot some metal on the high side and grind it to fit into keyway. Make it look like a farmer fixed it, damnit...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:Maybe I got lucky
https://www.fastenal.com/products/details/0437819https://www.qualitybearingsonline.co...nch/#tech-data
Reply:$24 for a lock washer? I'd still gob snot it with the welder...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:
Originally Posted by whtbaron
$24 for a lock washer? I'd still gob snot it with the welder...
Reply:just saw that... lol.... I'd still gob snot it to save me the trip...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:Fastenal was for "availability"Bearings Online store was for actual per piece price in the real worldEbay is for the bottom dollar price at my mailbox https://www.ebay.com/itm/13383775083...75.c101224.m-1Or.........I'll just wander down to the local parts store and pay about maybe 10ish dollars.Hard parts start with an image search, narrowed to sellers that have dimension specs in their description, then you look for the cheapest version of that particular part number. The Uranus Global Procurement Division is on the case
Reply:The engineering is sound, but I still hate your solution. I'd have thread filed the originals and made it work. For what it is... heck I'd probably have welded the nut back on, after all, you hope it shouldn't fail again in your lifetime...!Murphy's Golden Rule: Whoever has the gold, makes the rules.
Reply:Everything ground to yet another screeching halt yesterday.........just at the point of finishing up.I lost the lathe thread center gage. Looked for over 2hrs for it, and no luck. I finally gave up, and called it a day. 100 mile round trip to get a stinkin' $5 gage today I guess. And havin' to do it draggin' that stinkin' trailer full of pipe.Gotta haul pipe anyway, but the tool place is way off the highway, and I get miserable mileage off highway. And I'm too long to get in their parking lot access driveway. Have to park the damn thing on the street, and WALK.I probably lose at least an hour a day losing things. It's getting worse.
Reply:I did, however, find my nice 6" satin chrome 4r ruler yesterday
Was at the smoke shop, and sitting there waiting for the gal to get my carton, I looked sort of down at the dashboard........................and there it was.............tucked into the corner between the windshield, and the dashboard. Impossible to see unless you looked directly at it. It was just showing the thin edge.So....................I figure I ought to find the center gage sometime in December
Sam, you work hard, and you work clever, but you don't work smartWhy did you need to drive 100 miles for a gauge that you didn't even need? The lathe is still in the threading gears that you used to cut the external thread... why should the pitch change? And the threadform is meaningless... you just want a good fit between nut and shaft!So again, I don't get it. You're clever, and you work hard, but the concept of "work smart" has totally eluded you... must be old age
Murphy's Golden Rule: Whoever has the gold, makes the rules.
Reply:
Originally Posted by Munkul
Sam, you work hard, and you work clever, but you don't work smartWhy did you need to drive 100 miles for a gauge that you didn't even need? The lathe is still in the threading gears that you used to cut the external thread... why should the pitch change? And the threadform is meaningless... you just want a good fit between nut and shaft!So again, I don't get it. You're clever, and you work hard, but the concept of "work smart" has totally eluded you... must be old age
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:d:d:d
Reply:Sam, we built a world empire on the back of nelson's cannons, it was only after we started caring about precision that we lost our edge
Not being funny but it's a friggin bush hog. The shaft is already bent as a banana. You're trying to make a silk purse from a pig's ear.It's not going to care if the threads are squint. If the thread engagement is good, it will be fine. You've seen the tolerance on shop fasteners, most of them at slack as ****Most older machinists when they ground HSS for cutting threads just eyeballed it with a magnifying glass, unless it was ultra critical. Uranus Inc bush hog repair industries ain't critical
These days of course, most people use insert threadforms, which are already square to axis if your toolpost is on 90 degrees. That's all I use anyway. Lay flat inserts are a little bit more resilient to interrupted cuts than the upright style.Again, making a plug gauge for the nut. Why? You have a perfectly good shaft there to use as a gauge.I think i mentioned it already, but personally if I HAD to do what you were doing I'd have made the nut FIRST and use that as the thread gauge for the shaft threads.Work smarter, not harder!Last edited by Munkul; 19 Hours Ago at 08:16 AM.Murphy's Golden Rule: Whoever has the gold, makes the rules.
Reply:No wonder the Empire shrunk to a smidgeon
I dunno about other folks, but I use these to set the bit in relation to the stock that I'm ready to thread https://www.travers.com/product/ttc-...00-10%7CC%3A20 It's not just for grinding yer point.
Reply:Let me elucidate....................................... Videos seem to work. Pictures are better than words for some folks
Reply:Speaking of old school machinists.............................Got to 4:40ish on the video.
Reply:All that Lend Lease stuff,, which saved yer bacon
was made in this manner
Reply:It's not that I disagree with the technique, it's a good technique, definitely. (I'm time served, I know how to single-point thread)It's that I disagree with you on the level of precision required. You're not making perfect threads to an ISO spec for a customer miles away, you're making a custom nut for a custom thread, on a banana'd old shaft. As long as they fit one another nicely, that's all that matters.Like I say, you could have eyeballed that and it would have been fine.I bet you have a protractor that you could have used one way or another. or SOME form of getting the cutting tip as square as you can. But you chose to drive 100 miles with a trailer on the back, for a crappy $5 gauge that you somehow convinced yourself was required....No wonder you can't get on, Sam, for getting in your own way!I say all this from the comfort of the internet, knowing that in person I'd be far too polite to say it to your face. I'd smile and be respectful of your seniority. It wouldn't stop me thinking it, though.Murphy's Golden Rule: Whoever has the gold, makes the rules.
Reply:
Originally Posted by farmersammm
All that Lend Lease stuff,, which saved yer bacon
was made in this manner
Reply:Use a 60* carbide insert to set the threading tool with the shaft.
Reply:
Originally Posted by Munkul
Deflecting the issue won't shut me up
Reply:
Originally Posted by lars66
Use a 60* carbide insert to set the threading tool with the shaft.
Reply:To be clear.............the pipe yard where the J55 is to be returned, is in Tulsa on the same general route as the tool store (about 2 mi. off of I-44). So......on the way out of Tulsa, having to pass the exit to the tool store, I'll sashay on in and drop some coin.........before continuing on to the other pipe yard to pick up the 8". I'm just upset that I gotta actually WALK across the street cause I can't get in the parking lot with the 32' trailer
Reply:Why not just chuck up something with an existing 60 degree thread and set it to that? I can only imagine the dicking around to precisely set the compound to 29 degrees, 33 minutes and 13 seconds or whatever obscure angle is required to achieve NASA precision .
Reply:I guess a guy could make a nut, and while it's on the lathe TRY TO SCREW IN A 10LB FINE THREADED SHAFT TO SEE IF IT'S A GOOD FIT. Not this boyo
It's part of the reason I wasn't happy with the internal thread on the collet...........sure it fit for what I needed, but it had some fit issues if it was gonna be used as a for real nut.Or, I could remove the nut from the lathe, and try to see if it's a nice fit, then slap it back in the lathe to continue threading it
Be interesting to see how that turns out
Make a standard nut, and it should fit. Albeit I missed the pitch diameter on the shaft by .002 (mic was out of calibration when I originally checked diameter
, ta weren't .004 (British)
) . Machinery's says that the allowance on a 2B fit is .015 for the specs. So, ya gots a standard shaft thread, and a standard nut thread,,,,,,,,,,,,,,,,,,,,it should fit.Which is the point(threading joke
) of working to standards.
Reply:
Originally Posted by farmersammm
Here it is in British if there's a language barrier problem.....................(I can't stop
)
Reply:
Originally Posted by Munkul
That got a chuckle
Reply:
Originally Posted by farmersammm
Hey........you're one of the best. I always enjoy the banter. Makes my day. No kidding.Take care,, be safe, and have a good day/evening. I never know what time it is on different sides of the Planet.Gotta get my butt down the road with that stupid pipe
Reply:I Am A Freakin' Genius!!CSI: OklahomaFirst off.............no pipe.......tractor died
BUT!!!!!!!!!!!!!!!!!!!!!!!!!!!
I got out the little CSI flashlight, and wondered what Grissom might do...............Where could I have been when I misplaced the damn thing?Maybe dressing the point on the tool???????????
I'd looked here before......repeatedlyThis time I got out my little official CSI flashlightit had fallen edgewise between the dressing stoneand something else!!!!!!!!!!!We're On a Roll Here!!Tractor's been starting hard, or not startingHave to fiddle with the shutoff knob thingyI messed with that pump for almost half a daychecked flow from the tank clear to the pumpTHEN I DID THE UNTHINKABLE!!!!!!took off the cable connector.Grissom was whispering in my ear"Follow the facts"
Worn enough so's the shutoff lever on the pump doesn't openNo diesel.....no startLIFE IS SWEET!!!!Found my favorite ruler yesterdayFound my center gage todayAnd solved the fuel crisis
Reply:Now, back to yer regular programming.........................I specifically bought 12L14 to make a plug gage. It's one of the sweetest machining steels in the UNIVERSE.Yesterday, before the crisis
I used the carbide tool to make a gage.
I think I did a thread a few years back "Carbide Sucks" or something to that effect. THIS IS WHY I DON'T LIKE CARBIDE. That is the worst damn finish I've ever seen on a thread. It just plain sucks, and it's full of "noise" on the V's. Will be hard to tell if a nut rotates smoothly on that rough crap.Before I lost the center gage, I was gonna make another one with HSS. They only take about 15 minutes to make, so might as well verify two things........................ #1 Carbide still sucks for threading #2 Did the mope on Fleabay send me something other than 12L14 (it looks like the right stuff, but only machining will tell)I mentioned earlier that this particular tool is a NOS Dorian.......which has been discontinued. I'm wondering if the way the thing was designed is the problem..........therefore they quit making them. The insert sits in the tool in a neutral rake. It's the deal........no way to change it. I'm not at all certain that a relatively dull carbide insert will function well at a neutral rake when a good finish is desired. HSS will, but generally I think carbide won't. Before I get a shtstorm of negative replies............with carbide, the insert might sit neutral, but the profile is either negative or positive. Depends on the insert, and tool holder design. Although, I'm not certain that any form tool can sit at any other angle than neutral
I've experimented with this tool in the past................trying to justify keeping it, rather than chucking it over the fence into the pasture. I've set it below centerline, and no difference........it still just tears the metal, doesn't slice it.I hope I don't hit Bertha The Cow in the noggin when I toss this thing over the fence this evening.
Reply:This is what 12L14 should look like.
And it looks like this with a HSS bit. If it doesn't look like this tomorrow, somebody is gonna get a hot Email on Fleabay. If I had one of those mondo dollar XRF analyzers, it would be a done deal...........know for sure what I have.
Reply:"So....................I figure I ought to find the center gage sometime in December" Best way to find it is to start looking for something else...Last edited by whtbaron; 6 Hours Ago at 09:46 PM.250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:Need to chain it to a heavy large object like the old service station restroom key
Reply:
Originally Posted by M J D
Need to chain it to a heavy large object like the old service station restroom key |
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发表于 2021-11-9 15:51:35